Incorporation of platinum atoms in a silicon-free boride of the YB50-type structure

Abstract A new Pt-doped yttrium boride of the YB 50 family, YB 45−x Pt y , x = 2.12, y = 0.21 (space group Pbam , a = 16.6246 (4) A, b = 17.6453 (4) A, c = 9.4167 (2) A), has been synthesized by arc-melting pure elements and subsequent annealing at 1123 K. A single crystal has been studied in order to assess the Pt-doping effect on the crystal structure. Insertion of Pt in two 4 h interstitial sites of the boron atom framework leads to the transformation of –[B 12 ]–[B 12 ]– icosahedral chain into –[B 11 ]–Pt–[B 11 ]– for 38.6% of them as well as, to a lesser extent, induces disorder into the [B 15 ] polyhedron and neighboring interstitial B site (97.3% vs 2.7%).